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According to Haag, Man Wah workers knew before demolition that asbestos- containing material had been found at the school at 4314 Piedmont Ave. and that they were required to remove it under federal regulations.

But Haag said the employees demolished parts of the school without having a licensed subcontractor remove the asbestos, a hazardous air pollutant.

Man Wah's attorney, Chris Locke of San Francisco, said yesterday that the corporation has an "outstanding compliance record" and that the Piedmont demolition, like most school projects, took place over the summer, when students were not present.

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"It was completely isolated and completely cleaned up before school resumed, " Locke said, adding that tests conducted in July 1998, a month after the demolition, showed "no problems."

But San Francisco attorney Steve Harowitz, who regularly represents asbestos victims, said the students could potentially face health problems many years later, including mesothelioma, a cancer of the lining of the lungs or the abdominal cavity.

"I think there is a risk, even if there weren't kids at the time," Harowitz said. "There could be a release of fibers that could be reintroduced into the air."